And Labour MP Kate Hoey, one of the party's leading Eurosceptics, said Mr Cameron had been "absolutely right" to offer the public their say over the issue and she expected Labour to follow suit in due course.

BBC: EU exit would be 'fatal mistake' says Ken Clarke

The single currency would change Europe's labour markets because it would make it harder for governments to adjust macroeconomic policies to suit circumstances in their own economies.

ECONOMIST: Europe hits a brick wall